package main

import "fmt"

func main() {
	m := make(map[string]string)
	m["name"] = "allen"
	m["sex"] = ""

	v, ok := m["name"]
	fmt.Printf("v = %s, ok = %v\n", v, ok)

	v, ok = m["age"]
	fmt.Printf("v = %s, ok = %v\n", v, ok)

	v, ok = m["sex"]
	fmt.Printf("v = %s, ok = %v\n", v, ok)

	v = m["name"]
	fmt.Printf("v = %s\n", v)

	v = m["age"]
	fmt.Printf("v = %s\n", v)

	v = m["sex"]
	fmt.Printf("v = %s\n", v)
}
